3.3. How Can I Run a Process Every Night To Kill Certain Connections?

Some database administrators use nightly routines to perform
maintenance on their databases or servers. Sometimes these
routines can be blocked by long running queries or applications
that hang onto locks for longer than expected.

Naturally, priority is given to the application and maintenance
routines are often cancelled rather than interfere with an
application. Should it happen that you subscribe to this notion
and you have a routine that is still being blocked or for some
reason hasn't completed by a certain time, you need a quick way to
generate an event to kill the connection involved. This is where
the mysqlprocgrep utility can help.